661187467 has 2 divisors, whose sum is σ = 661187468. Its totient is φ = 661187466.

The previous prime is 661187459. The next prime is 661187531. The reversal of 661187467 is 764781166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661187467 - 2³ = 661187459 is a prime.

It is not a weakly prime, because it can be changed into another prime (661187767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330593733 + 330593734.

It is an arithmetic number, because the mean of its divisors is an integer number (330593734).

Almost surely, 2^661187467 is an apocalyptic number.

661187467 is a deficient number, since it is larger than the sum of its proper divisors (1).

661187467 is an equidigital number, since it uses as much as digits as its factorization.

661187467 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 46.

The square root of 661187467 is about 25713.5658165102. The cubic root of 661187467 is about 871.1806171612.

The spelling of 661187467 in words is "six hundred sixty-one million, one hundred eighty-seven thousand, four hundred sixty-seven".